Lattimore said Harbaugh "stressed" to him to take his time recovering from what was his second major knee injury in as many seasons, having torn the ACL in his left knee in 2011.

While Harbaugh called it premature to count out Lattimore this season, the coach added: "He's got to take a step back with cutting, because we want the inside of his knee to heal." Lattimore is limited to an observer's role for the 49ers' three-day, rookie camp that began Friday. He's OK with sitting out all season if that's what the doctors order.

"That'll be fine. Whatever happens over the next few months will determine that," Lattimore said. "If I'm called upon, hopefully I'll be ready." Lattimore was drafted two weeks ago in the fourth round. South Carolina coach Steve Spurrier, himself a one-time 49ers draft pick, offered advice to his former star running back: "He told me about the weather and how nice it was. And he said, 'Keep being yourself and you'll be fine.' " Lattimore has not yet met 49ers running back Frank Gore, who reached out and consoled Lattimore after he tore three ligaments against Tennessee on Oct. 27.